Say.., the Java compiler erases all type info, and replaces all occurrences of those with their upper bounds (if mentioned) or Object..
My questions is: no insertion of casts takes place here. Casting occurs later when some other class is compiled against this type info-free class, where, depending on the type argument(s) that other class supplements, the generic class is recompiled (for a second time) and all casts are put in place and the class is ready for run time.., right?
No, the class is not recompiled. The casts happen on the boundary between concrete and generic types.
If you're trying to figure it out, you could look at using a generic class as a raw type (i.e. without the generics). For instance ArrayList:
List l = new ArrayList(); // An `ArrayList<String>` before generics.
l.add("Hello");
String s = (String) l.get(0);
The casts are inserted where the concrete type is known (String in this case). They are not inserted inside the ArrayList class, and there isn't really a need for that.